In the last decades, the academic and clinical knowledge and understanding of brain processes and diseases have considerably improved and so have the medical and surgical treatments of such pathologies. One field of brain medicine which has particularly developed is the field of neuromodulation techniques, which consist in submitting brain areas to a physical stimulation like an electric current or a magnetic field to treat a neurological disorder. Among neuromodulation techniques, DBS (which stands for “Deep Brain Stimulation”) with electrical probes, TES (which stands for “Transcranial Electrical Stimulation”) and TMS (for “Transcranial Magnetic Stimulation”) are well known and exemplified in literature.
Recently, it has been proposed in WO 2006/092061 A1 implantable devices to cause lasting changes in neural functions through several types of physical stimulation (mechanical impulsion on cortex, electrical deep brain stimulation, drug infusion, for neurological deficit rehabilitation). It has also been suggested in WO 2009/067323 A1 devices for creating a skull/brain interface, which devices (implantable into the skull) are totally passive windows or channels permeable to external physical means (electric ionic current, radiofrequency . . . ) in order to neuromodulate brain activity for movement disorder or epilepsy pathologies.
In the field of brain cancer treatment, such neurostimulation techniques are not efficient. The treatments applied to this pathology remain the same as those applied for any kind of cancer, i.e. chemotherapies and/or surgical ablation of tumors when it is possible without irreversible or lethal damaging of the brain.
Surgical treatments of the brain require open surgical procedures in the skull of patients. Such open surgical procedures comprise a craniotomy, which includes performing a bone flap.
To do so, the surgeon firstly performs a trepanation in the skull by piercing several burr holes, and secondly unsticks the durra matter underneath. After that, the surgeon then performs the craniotomy by using a saw going from one burr hole to the other. Burr holes are usually 10 to 12 mm diameter each. The fragmented bone chip of each burr hole is kept and used at the end of the surgery to fill bone defects, which suffer poor, long-term, ossification. At the end of the surgical procedure, the bone flap is repositioned and fixed either with trans-skull stitches or with titanium micro-plates. The bone defect areas are filled up either with a synthetic copolymer or with bone powder obtained from the drilling of the burr holes at the beginning of the procedure.
These craniotomy procedures are heavy to support for the patients and leave irreversible traumas in the skull.
Ultra keyhole surgical procedures do not require performing a bone flap, but only a burr hole. This burr hole can be very slight (4 mm diameter) in cases of stereotactic biopsy, but can be larger (between 8 to 12 mm diameter) for endoscopic procedures required for partial ablation of tumors.
Where chemotherapeutic treatments are concerned, these treatments include administration of highly active drugs to the patients. Unfortunately, these drugs are not specifically active onto the tumors and they also have considerable negative effects in the whole body of patients, with very unpleasant side-effects like nausea, hair loss etc. . . .
For some years now, high intensity ultrasounds have shown to be a relevant physical mean to treat tumors by their capacities to thermo coagulate the tissue (high intensity ultrasounds). However, in the brain, such ultrasound treatments are by now ineffective due to the skull barrier that absorbs and diffracts ultrasounds waves.